Bash Scripting

[Droopy]

Help,

I need to write a script that prints the longest filename in a directory. The directory is supplied as an argument to the script. I have no problems supplying and checking the argument, but am a bit lost after that. I tried the following

for file in "$( find $1 -size +0)"
do
strlen=${#file}

if [ "$strlen" -gt "$filelen" ]; thne
filelen=$strlen
filename=$file
fi
done

echo "Filename is $filename"

can anyone help, in desperation

Drew

[Franklin52]

Hi,

This would do the job:

#!/bin/sh

if [ -z "$1" ]
then
  echo "Usage: `basename $0` directory-name"
  exit 1
fi

cd $1

let "maxlen=0"

for line in *
do
  strlen=`echo ${#line}`
  if [ -f "$line" ]
  then 
    strlen=${#line}
    if [ $maxlen -lt $strlen ]
    then 
      let "maxlen=strlen"
      longestfilename=$line
    fi
  fi
done

echo $longestfilename : $maxlen

exit 0

Check the man page for the test command and look through a couple of scripting tutorials:

http://www.tldp.org/LDP/Bash-Beginne...tml/index.html
http://tldp.org/LDP/abs/html/

Any doubts? Feel free to ask more questions.
And... your code would be easier to read if you placed it in CODE blocks!

Regards

[Droopy]

Hey all,

I need to find the starting character to a string provided as an argument to a script.

I thought that this would work:

firstch=`grep -e ^.{1} --label='hello'`

Im using the literal 'hello' to test the command

echo $firstch

I want firstch to equal 'h'


thanks in advance

Drew

[Droopy]

I sorted the previous one, I'm trying to check all the supplied arguments

while [ $currentarg -le $$numofargs ]; do
if [ ! -f ${$currentarg} ]; then
echo "File does not exist"
exit 1
else
( $currentarg ++ )
fi
done

What is wrong with the variable substitution?

if [ ! -f ${$currentarg} ]; then

[Franklin52]

Are you trying to test the parameters of your script? And are you expecting directory names as parameters? The -f operator returns true if the substituted variable is a regular file.

To test how variable substitution or whatever works, write a little script like this:

#!/bin/sh

currentarg=$1

if [ ! -f "$currentarg" ]; then
  echo $currentarg is not a regular file
fi

Use shift to read the next parameter within a loop, have a read of this:

http://www.tldp.org/LDP/Bash-Beginne...ect_09_07.html

If you want to really learn it, it is suggested that you learn by reading and experiencing it yourself.

And place questions about scripting in the "Linux Programming & Scripting" section.

Regards

[tpl]

if "hello" is a file containing its own name, these work OK:

firstch=`cut -c 1 <hello`

firstch=`dd bs=1 count=1 2>/dev/null <hello`

firstch=`awk '{print substr($0,1,1)' <hello`